UK Police criticised for not arresting man carrying IS flag near parliament

 British capital of London have been slammed for their failure to detain a man purportedly wandering near the parliament building while draped in a flag of the Takfiri IS terrorist group

The Metropolitan police in the British capital of London have been slammed for their failure to detain a man purportedly wandering near the parliament building while draped in a flag of the Takfiri IS terrorist group. 
The individual was photographed walking past a group of Scouts outside the British legislative Houses while wearing the flag on his back and carrying on his shoulders a small child waving a smaller IS flag, UK-based daily The Guardian reported. 
Images of the man and the child were reportedly posted on an online Korean forum after a tourist witnessed them in central London. 
This is while London’s Metropolitan police confirmed in a statement that officers did observe the man but did not take him into custody since they did not consider his behavior to be unlawful. 
However, the police failure to arrest the man was harshly criticized in social networking sites, challenging wider concepts of public safety as perceived by law enforcement authorities. 
The British government estimates that more than 700 radicalized UK citizens have joined the IS terrorist group.